Improvement in mandrels for welding tubes



s. P. M. TAsKERJ Mandrels for Welding Tubes.

Patented April 28,.1874.

.NTTED STATES STEPHEN P. M. TASKER, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN 'MANDRELS' FR WELDlNG TUBES.

Spetilieation forming part of Letters Patent No.150,374, dated April:38, 1874; application tiled April 4, 1874.

To all uhom it may concern:

13e it known that I, STEPHEN I". M. TASKER, ot' the.V city and eountyot' Philadelphia, in the. State ot' Pennsylvania, have invented anImprovement in Mandrels and Mandrel-Bars'for lllanut'aeturing MetalTubes, of which the fol'- lewin g is a speeilieation:

My invention rela-tes t0 the construction of the bar with loose maudrelsfor eaehpair Ot' rolls when more than one pair of rolls is used in amaehine, and when an internal resistance is required against thepressure of the rolls,

ln thel manufacture of metal tubes, when one pair ol' rolls is used themandrel is usually ot' eonieal torm, and is placed on a pin on the endot' the bar 5 but in using two or more pairs ot' rolls, the eonnnon modehas been to have the mandrels put on the bars as swells, either made.i'astas part ot' the bar, or held on by serews or other means, making itditlieult to ehan ge the mandrels without changing' the bar and themandrels atthe same time.

l 3 y m y improvement I am enabled to change the mandrels as easilyv aswhen one pair of rolls is used. 'lo accomplish this purpose I have ashoulder formed on the bar for the inner ball to rest against. This'shoulder l usually make by reducing the end of the bar. 135' this meansl maintain its strength, to more eiteetuall y resist the great strainagainst it as atube is passing over thel mandrels. rlhe bar, however,can be made ofthe reduced site throughout its whole length, byliaving acollar put on to support the inner mandrel. The outer or end mandrel eaube held by the end of the nmndrel-lair takin g the thrust, or by meansot' a shoulder. l use, in combination with the mandrels, aeonneeting-pieee, which is avery little smaller in diameter than themandrels, to avoid frietion. This middle 4pieee is intended to sustainthe tube as it passes over the mandrels. ylt is otl great advantage inease ot a tube sticking on the inner mandrel while the motion is stillaetive on the end mandrel, whieh has the tendency to make the tubelaiekle up, making it -dillieult to remove the mandrel from the tube,and ot'ten causing breakage in the machine. rlhe eoiuieetingmandrels Band 13/ with the mandrel-bar A.,

Figs. 4 and 5 represent like eonneetions ot' the mandrels, with thepiece (l in combination therewith. v

Like letters ot referenee in all. the figures Vindicate the same parts.

A represents the maiulrel-bar; l the inner, and 13 the outer, mandrel.ln lrigs.. l and -t the main portion ot' the bar is larger than the endportion, so as to insure great' strength to resist the strain upon it asthe tube is passing over the mandrels, the end portion A' being rodueedto receive the outer mandrel l3,'and -to form a shoulder at ato resistthe thrust ot' the end ofthe inner mandrel l. rlhel mandrelbar may,however, b'e of uniform size throughout its whole length, in whieh easel form. the shoulder a, t'or the inner mandrel l to .rest against, bymeans ofthe eollarb. (Seen in lfigs. 2 and It' desired, the outer part Aoi' the mandrel-bar may have a shoulder, u', to receive the inner end ofthe mandrel ll', as seen in Fig. 3. The end part A ot' the mandrel-lairmay be either round, square, or other t'orm.

l have represented the mandrels, as to t'orm, like those in genera-luse; yet any deviation therefrom may beadopted without depui-tin from'the prineiple ot' in v invention.

` In Figs. EL and 5 l have represented al piece.,

C, on the part A of the bar, between the inner and outer mandrelsl lland l'. The object is to prevent the tube being buekled inward by thepressure ot' the rolls when the tube sticks to the inner mandrel ll,whieh sometimes oeenrs. 'lo prevent friet-ion on this inner pieee as thetubes pass over it, it is made. slightly smaller than 'the mandrels, butlarge enough to prevent the buckling of the tubes when they stiek to themandrel l. 'lhe said middle piece bein g smaller than the mandrels, andnot being rubbed Vagainst by the tubes except when the sticking occurs,it `does not weer outlike the mendrels7 and, consequently, seldom has tobe renewed.

I have only represented two mandrcls to a bar, yet it will be seen that:my nulnbcrm ay be used corresponding to the number of pairs of rolls.

The mandrels B and B', and the piece C, are loose upon the mandrel-bar,so as to drop off for cooling as the bar is withdrawn from the tube.

I cla-im as myinvention- 1. The mandrel-bar A, having a projectingpiece, A', to receive the inner and outer mandrels B and B', and. a.shoulder, a, to resist the' thrust of the inner mandrel B, substantiallyin the manner and for the ypurpose described.

2. The combination of the piece C with the part A of the mandrel-bar,and the mandrels B and B', substantially as and for the purpose Setforth.

STEPHEN P. M. TASKEP.

Witnesses: A

THoMAs J. BEWLEY, STEPHEN UsirIoK.

